Comments: Hydrolyses the 1,4-β-D-galactosyl linkages adjacent to 1,3-N-acetyl-α-D-glucosaminyl residues. Also acts on some non-sulfated oligosaccharides, but only acts on blood group substances when the 1,2-linked fucosyl residues have been removed (cf.EC 3.2.1.102 blood-group-substance endo-1,4-β-galactosidase).